Fluid indicator and metering device



May 12, 1942. Y. NEAL 2,282,528

FLUID INDICATOR AND METERING DEVI CE Filed Feb. 18, 1959 IHIHIIIII Mllllllllk inn/ IIIIIIIH v INVENTOR! BY Younger Neal ATTORNEY.

Patented May 12, 1942 FLUID INDICATOR AND METERING DEVICE Younger Neal, Ohicago, l ll., assignor to The Pure Oil Company, Chicago, 111., a. corporation of Application February 18, 1939, Serial-No. 257,073

3 Claims. (Cl. 73-194) This invention relates to plunger type fluid indicating and metering devices more particularly for use in connection with force feed lubricators.

In patents numbered 2,047,715 and 2,136,261

there are disclosed and claimed devices of the general nature of the device constituting my invention. My device, however, includes certain modifications and improvements not shown in the aforesaid patents.

In my improved device I have provided a transparent cylinder, preferably made of a nonfrangible composition material such as Bakelite, inwhich a plunger is adapted to freely reciprocate. The transparent cylinder is fitted with a metal sleeve insert which is adapted to snugly fit the plunger as it reciprocates. The transparent cylinder is preferably encased by or pressed into a metallic cylinder having one or more slots therein, to permit observation of the plunger. The arrangement of plunger, valve and springs is such that the device will operate with oil of substantially any viscosity and with any type of lubricator without necessitating any adjustment. The device is leak-proof without the necessity for using washers or packing material.

In the devices of the prior art it has been found that wide variations in temperature cause the cylinder to contract to such an extent that the plunger binds against the transparent cylinder with such' friction that the plunger sticks and will not reciprocate as is necessary to satisfactory operation. Sticking also occurs due to tiny particles of metal, dust and dirt, carried by the lubricating oil, which find their way between the cylinder and plunger when the cylinder expands, the particles embedding themselves in the relatively soft cylinder walls and wedging between the plunger and cylinder. As a result of these difiiculties the plunger sticks and the valve dart remains open so that lubricant feeds through the device without any indicating or metering being effected.

These difiiculties have been entirely overcome and an improved operation effected by using a metal sleeve insert or bushing in the transparent cylinder, in which the plunger fits very closely, and by providing a relatively wide clearance between the plunger and the transparent cylinder. With these changes the plunger does not bind against either the transparent cylinder or metal bushing over wide variations in temperature. The metal bushing provides a surface sufiiciently hard so that the small particles cannot become embedded therein.

The nature of the improvements which I have effected will be clearly evident after reading the following description in conjunction with the accompanying drawing, of which Figure 1 is a full size, vertical cross-sectional view of the device in accordance with my invention taken on the line Il of Figure 2.

Figure 2 is a diagrammatic elevational view of the device. t

Figure 3 is a horizontal cross-sectional view of the casing of the device taken on the line 33 of Figure 2. v

Referring to the drawing, the numeral l indicates an open-ended cylindrical metallic casing having therein one or more slots 3 intermediate the ends thereof. As shown in Figure 3, there are three slots inthe casing. The upper end of the casing is internally threadedat 5 in order to receive the top closure 1. The lower end is internally threaded at '9 in order to receive the lower closure I l. The casing l is preferably'die-cast out of suitable metal or it may be made by drilling, forging or other operation. The inside wall I3 is machined to a smooth'slid ing surface. The upper and lower closures "I and II are also preferably die-cast with the passageways I5 and'll'respectively. The upper end is threaded at'l'9 to receive a suitable pipe nipple and at 21 to screw fit into the upper end of the casing l. The lower end II is threaded exteriorly at 23 to screw fit into the casing I and. at 25 in order to receive a suitable coupling. A transparent cylindrical hollow tube 21, preferably of non-frangible composition, is pressfitted in the casing I intermediate the ends thereof. In order to properly fitthe tube 21 in the casing, it is first hollowed by drilling a hole therethrough of the approximate diameter desired. The tube is then pressed into the casing through one end thereof so as to fit tightly therein without leaking. The tube 21 is then broached or reamed to the desired diameter. Suitable material for making'the tubing is transparent Bakelite or other organic condensation products. The outer surface of the tubing 2'! is machined to substantially the same diameter as the inner diameter of the casing l thereby enabling a tight fit to be made without the necessity for using washers or packing material. The tubing Z'l should be sufficiently long to extend beyond the ends of the slot 3 and to permit insertion of a metal bushing 29 which furnishes the sliding surface for a plunger to be subsequfil tly deg scribed. The metal bushing is press-fitted in the upper portion of the cylinder 2'! which has been reamed to a'larger diameter than the bore ably stops short of the upper face 32 of the lower end I! and the upper end of the tube stops short of the inner face 33 of the closure 1.

A hollow cylindrical plunger 34 of known displacement is lapped into the bushing 29 so that it is adapted to fit snugly therein and loosely within the tube 21 and reciprocate therein. The clearance between the bushing and plunger will be approximately of an inch while the clearance between the cylinder and plunger will be approximately of an inch. The bottom face 35 of the plunger has a narrow opening 36 at the center thereof connecting with the hollow portion of the plunger. A shoulder 31 is formed on the inside wall of the plunger a short distance from the upper end thereof. The relative lengths of the bushing and plunger are such that the outer surface of the plunger is at all times in sliding contact with the inner surface of the bushing.

An elongated valve dart 39 is loosely mounted within the plunger 34 and is adapted to move therein. The lower end of the valve dart is formed with a tapered point 4| which is adapted to seat in the opening 36 and form a closure therefor. A short distance above the lower end of the valve dart a horizontal passageway 43 is bored therethrough and connects with a longitudinal passageway 45 which extends to the upper end of the valve dart. A shoulder 41 is formed on the inner wall of the valve dart inter mediate the passageway 43 and the upper end of the dart.

A relatively low tension coil spring 49 is mounted in the passageway 45 of the valve dart with the lower end of the spring abutting against shoulder 41 and the upper end thereof extending beyond the upper end of the dart. A spring follower 5|, having a passageway 53 through the center thereof, is mounted in the upper end of the plunger 34 and is of such diameter that it cannot pass downwardly beyond the shoulder 3! of the plunger 34. The follower 5| is adapted to slide in the upper end of the plunger 34. The upper end of the spring 49 is adapted to abut against the lower surface of follower 5|.

A second coil spring 55 of relatively high tension is mounted in the upper end of the device in the passageway 3|. The lower end of this spring abuts against the upper face of the follower 5| while the upper end of the spring abuts against the shoulder 51 formed in the passageway 3|. The tension of the springs to be used will depend in a large measure upon the relative weights of the valve dart and plunger, the area of the opening 36 and the area of the bottom face of the plunger exposed to fluid pressure, but I have found that in a device of the size shown herein, the spring 55 may be of such tension that a force of .35 pound is required to compress it one inch, whereas the spring 49 may be of such tension that a force of .15 pound is required to compress it one inch. With springs of this relative tension the device can be used with oils of substantially any viscosity.

The edges of the slot 3 may be bevelled as shown at 59, and the sides of the slot may be calibrated as shown at 6| in any units, preferably cubic centimeters.

The device operates as follows: Oil is pumped into the device through the passageway I! at which time the bottom 35 of the plunger 34 rests on the inner face 32 of the lower closure The effective force due to pressure of the oil on the bottom face of the plunger being greater than the effective force due to pressure on the portion of the valve dart exposed to the oil, the plunger will rise with the valve in closed position. While the valve is rising the spring follower 5| will be 7 seated on the shoulder 31 and the spring 55 will be gradually compressed. The plunger is forced upwardly until the upper end thereof strikes the face 33 of the closure 1 and its upward motion is stopped. At this instant valve 39 rises thereby opening the passageway 35. The spring 55 quickly forces the plunger 34 downwardly to its initial position with its bottom face resting on the inner face 32 of the lower closure displacing the fluid contained in the lower portion of the device and forcing it up through the opening 36, around the side of the valve, through the passageways 43, 45 and 53, into the space above the plunger. The combined action of the spring 55, follower 5|, and spring 49 also forces the valve dart back to its initial position, but due to the fact that the spring 49 is lighter than the spring 55 and due to the resistance of the velocity head of oil passing through the opening 36, the valve will lag somewhat behind the plunger thereby permitting the plunger to reach its lower-most position before the opening 36 is 'closed. vUpon the return of the plunger'and valve to the lowermost position, the cycle starts over again. During the upstroke of the plunger the oil in the space above it is forced out through the'passageway l5.

By placing a visible line or band 63 around the outer periphery of the plunger 34, the distance of upward travel of the plunger can at all times be easily observed through the slots in the casing,

and if desired, by observing the time required for the line to travel from one position to another position on the scale, the volume of fluid pumped in any given time can be determined.

Since there is a small clearance between the plunger 34 and tube 2'! and since plunger 34 and bushing 29 have approximately the same coefficients of expansion, there is no trouble to be encountered by changes in size due to thermal expansion or contraction. Fouling of the device by means of dirt getting between the plunger 34 and tube 21 or bushing 29 is also eliminated. The clearance between the transparent cylinder and the plunger is sufficient to permit of maximum contraction of the cylinder without freezing the plunger but sufficiently small to guide the plunger during reciprocation thereof.

The outer casing and closures of the devices made in accordance with my invention are preferably cast from bronze or brass but may be made by any other suitable operation. The plunger may be made of steel or other metal, the principal requirement being that 'a material be used that has approximately the same coefficient of expansion as the bushing which is made of brass, bronze or a similar metal. The valve, springs, etc., forming the remainder of the inner mechanism, are preferably made of steel. It will be apparent that glass may be used in place of nonfrangible material but with consequent loss of the advantages attendant upon press-fitting and absence of washers and packing material.

It will be understood that although I have shown a specific modification of my invention, the invention is not limited to the modification shown, but is intended to cover broadly the novel features shown and described herein.

What I claim is:

1. An indicating and/or metering device comprising a metallic casing, a transparent, nonfrangible, hollow cylinder press-fitted into said metallic casing, a metallic sleeve press-fitted into one end of said cylinder, said sleeve having an in side diameter slightly less than the inside diameter of said cylinder, a closure on each'end of said casing, said closures each having a passageway therethrough connecting with the hollow portion of said cylinder, a metallic plunger snugly fitted in said sleeve, said plunger being adapted to snugly reciprocate in said sleeve and to loosely reciprocate in said cylinder, a slot in said casing through which said plunger is visible, said plunger being caused to advance by means of fluid pressure, and means operable to cause said plunger to resume its initial position when it reaches the end of its advance stroke.

cludes a visible line on the plunger and calibrated markings on the slot in the casing whereby fluid passing through the device may be accurately I measured.

3. An indicating and/or metering device com- M prising a metallic casing, a transparent, nonfrangible, hollow cylinder press-fitted into said metallic casing, a metallic sleeve press-fitted into I when it reaches the end of its advance stroke, a-

slot in said casing, said slot and said metallic sleeve being formed in such relation that the metallic plunger is at all times visible through said slot.

YOUNGER NEAL.

2. Device in accordance with claim 1 which in- 

